CBSE Questions for Class 12 Medical Biology Microbes In Human Welfare Quiz 9 - MCQExams.com

A biological control which is effective biocontrol agent for several plant pathogens : 
  • Nucleopolyhedrovirus
  • Tirchoderma
  • Agrobacterium
  • Bacillus
The Rhizobium bacteria lines inside the root nodules of ________.
  • Pea plant
  • Beans
  • Peanuts
  • All of the above

Chlorine treatment
  • Removes all the air pollutants
  • Disinfects water by killing germs
  • Removes hardness of water
  • All of the above

Activated sludge should have the ability to settle quickly so that it can

  • Be rapidly pumped back from sedimentation tank aeration tank.
  • Absorb pathogenic Bactria present in waste water while sinking to the bottom of the settling tank
  • Be discarded and anaerobic ally digested
  • Absorb colloidal organic matter
In which of the following industries, microbial enzymes are not used?
  • Glass industry
  • Cheese industry
  • Tanning industry
  • Paper industry
In which of the following industries, microbial enzymes are not used?
  • Glass industry
  • Cheese industry
  • Tanning industry
  • Paper industry
How is the lactic acid fermentation used in milk industry?
  • To convert milk sugar to lactic acid
  • Lactic acid coagulate the milk protein casein
  • Lactic acid coagulate the milk fats
  • All of the these
Anaerobic sludge digesters and inoculums are part and parcel of _____________.
  • Primary sluge
  • Activated sludge
  • BOD
  • FIocs
Instead of using chemical fertilizers in a paddy field, a farmer thought of employing nitrogen fixation technique. Amongst the following which would be beneficial for his cause?
  • Glycine max - Rhizobium
  • Cycas - Nostoc
  • Casuarina - Frankia
  • Azolla - Anabaena
Citric acid used in the production of beverages, toffees, chocolates is obtained by fermentation of _______ by Aspergillus niger.
  • Wheat
  • Sugar molasses
  • Rice
  • Coffee nuts
Microbes those can be used as biofertilizer:
  • Rhizopus, Anabaena, Cercospora
  • Rhizopus, Trichoderma, Azotobacter
  • Azotobacter, Anabaena, Glomus
  • Trichoderma, Cercospora, Glomus
The bacteria nostoc are used as food because they have abundant amount of ________ and _______.
  • Proteins and vitamin C
  • Carbohydrates and lipids
  • Water and vitamin D
  • Carbohydrates and proteins
Which of the following is a function of Rhizobium?
  • Denitrification
  • Nitrogen fixation
  • Ammonification
  • Nitrification
Which one of the following is not used as biofertilizer?
  • Bacillus thuringiensis
  • Anabaena
  • Nostoc
  • Rhizobium
How many of the following organisms can be used as biofertilizers?
Azolla, Thiobacillus, Frankia, Glomus, Pseudomonas, Anthoceros, Klebsiella.
  • $$3$$
  • $$5$$
  • $$2$$
  • $$1$$
Benzo-diazepene is an?
  • Anti depressant
  • Anti psychotic
  • Anti anxiety drug
  • Sedative
Match the contents of Column-I with of Column-II.

Colum-I
Column-II
AMonascus purpurensiStatins
BAspergillus nigeriiCyclosporin-A
CTrichoderma polysporumiiiCitric acid
  • A-i, B-ii, C-iii
  • A-i, B-iii, C-ii
  • A-iii, B-i, C-ii
  • A-ii, B-i, C-iii
Which one is the most important role of microorganisms for the well being of humans?
  • Sewage treatment
  • Production of methane
  • Conversion of milk to curd
  • Biological control of plants disease
Which of the following is the pair of biofertilisers?
  • Azolla and BGA
  • Nostoc and legume
  • Rhizobium and grasses
  • Salmonella and E.Coli
Which of the following statement is incorrect?
  • Biofertilizers are used to maintain and improve soil fertility
  • Chemical fertilizers pollute soil and water resources
  • Chemical fertilizers are expensive
  • Most pesticide used these days are specific in nature
Which of the following is correct about biogas?
  • Methane gas is produced along with ethyl alcohol by methanogen
  • Methanogens acts on cellulose and release biogas
  • Biogas is produced by thunder and lightening
  • Maximum gas found in biogas is $$CO_2$$
Secondary treatment is also known as ________________.
  • Biological Treatment
  • Preliminary Treatment
  • Secondary Treatment
  • Tertiary Treatment
The microorganisms involved in floc formation during sewage treatment are 
  • Anaerobic bacteria and fungus
  • Aerobic bacteria and fungus
  • Autotrophic bacteria and yeast
  • Fungus and algae
In secondary treatment, solid reducers, ranges from
  • 70-92%
  • 80-90%
  • 20-60%
  • 10-70%
The gas released during the preparation of bread is
  • Oxygen
  • Nitrogen
  • Carbon dioxide
  • Sulphur dioxide
Secondary treatment is carried out for removal of;
  • Suspended solids
  • Dissolved organic matters
  • Floating materials
  • Solid impurities
The gases produced in a digestion tank have --------.
  • Calorific value
  • Density
  • Gas Value
  • Digestion Value
The prickly pear weed (Opuntia) became a menace and it has been successfully controlled by
  • DDT spray
  • Cattle
  • Destroying its seeds
  • Cochineal insects
A legume having symbiotic association with two nitrogen fixing bacteria (Rhizobium and Aerospirillum) is
  • Crotalaria juncea
  • Sesbania aculeata
  • Sesbania rostrata
  • Cyamopsis tetragonoloba
Third generation pesticides are ?
  • Insect repellents
  • Pheromones
  • Pathogens
  • Insect (juvenile) hormone analogues
Farmers have reported 50% higher yield of rice by using which bio-fertilizer?
  • Azolla pinnata
  • Legume - Rhizobium symbiosis
  • Cyanobacteria
  • Mycorrhiza
If wheat field is inoculated with Rhizobium, then
  • Soil will become nitrogen rich
  • No effect on soil nitrogen
  • Soil will be depleted of nitrogen
  • Soil will become rich in calcium
Which one of the following, proved effective for biological control of nematode diseases in plants?
  • Gliocladium virens
  • Paecilomyces lilacinus
  • Pisolithus tinctorius
  • Pseudomonas cepacia
Green manuring enhances crop yield by
  • 5 - 10%
  • 15 - 25%
  • 30 - 50%
  • 60 - 70%
Biofertilizers include
  • Cowdung manure and farmyard waste
  • A quick growing crop ploughed back
  • BGA/Anabaena azollae
  • All of the above
Which disease is caused in children due to excessive use of nitrate fertilizers?
  • Septicemia
  • Jaundice
  • Methaemoglobinaemia
  • Mumps
What is required for nitrogen fixation by Rhizobium?
  • Potassium
  • Phosphorus
  • Molybdate
  • Sodium
Microspores of massulae in Azolla are found in
  • Inducium
  • Sporangium
  • Antheridium
  • Archegonoum
For the manufacture of gluconic acid and citric acid, which of the following micro-organism is used?
  • Lactobacillus bulgaricus
  • Acetobacter sp.
  • Aspergillus niger
  • Gluconobacter sp.
Cochineal insect has been used in checking the wild growth of
  • Opuntia
  • Eichhornia
  • Aphids
  • Screw worm
Methane content of biogas is
  • 24.6%
  • 55.8%
  • 8%
  • 4%
The domestic sewage in large cities
  • Is processed by aerobic and then anaerobic bacteria in the secondary treatment in Sewage Treatment Plant (STPs)
  • When treated in STPs does not really require the aeration step as the sewage contains adequate oxygen
  • Has very high amounts of suspended solids and dissolved salts
  • Has a high BOD as it contains both aerobic and anaerobic bacteria
Algal fertilizers are made up of
  • NPK rich in Nostoc
  • NPK with Anabena
  • NPK in ratio of 10 : 14 : 10
  • Combination of Azolla and Anabena
Jute is obtained from
  • Cannabis sativa
  • Corchorus capsularis
  • Linum usitatissimum
  • Aloe vera
Which one of the following is an example of carrying out biological control of pests / diseases by using microbes?
  • Trichoderma is used against certain plant pathogens.
  • Nucleo polyhedrosis virus is used against white rust in Brassica.
  • Bt-cotton is used to increase cotton yield.
  • All of the above.
Vitamin B$$_{12}$$ is produced directly during the course of fermentation by
  • Ashbya gossypii
  • Rhizopus stolonifer
  • Saccharomyces cerevisiae
  • Propionibacteria
An organism used as biofertilizer for raising soybean crop is 
  • Nostoc
  • Azotobacter
  • Azospirillum
  • Rhizobium
Bioaugmentation is 
  • The addition of commercially prepared bacterial strains with specific catabolic activities to degrade wastes
  • Production of fertilizers by using bacteria
  • The metals are deposited as insoluble oxides and sulphides by activity of bacteria
  • Removal of pests
Starter culture are useful and specific microbes for ?
  • Removal of pests
  • Biofertilizers
  • Biodegradation in xenobiotics
  • Sewage degradation
Modern detergents contain enzyme preparations of 
  • Acidophiles
  • Alkaliphiles
  • Thermoacidophiles
  • Thermophiles
0:0:1


Answered Not Answered Not Visited Correct : 0 Incorrect : 0

Practice Class 12 Medical Biology Quiz Questions and Answers